1. Field of the Invention
The present invention relates generally to the field of exercise equipment. More particularly, the invention relates to an exercise device having a cable and pulley system that offers two different levels of resistance at a pull point, independent of the amount of weight selected.
2. Background
Exercise equipment having a cable and pulley system for lifting a stack of weights has been in use for well over a century. Such equipment comes in a wide variety of designs for performing various exercises. One type of such exercise equipment, exemplified, for example, in U.S. Pat. No. 4,402,504, is particularly suited for upper body exercises. This apparatus has an elongated upstanding frame and a carriage that is movable up and down along vertical posts of the frame. The carriage includes one or more pulleys around which a cable is reeved. The cable is further reeved around upper and/or lower pulleys on the frame and is coupled to a source of exercise resistance, such as a plurality of stacked weights. The cable exits the pulley on the carriage and is connected to a handle or similar pulling device. The height of the handle is readily adjustable by moving the carriage on the vertical posts and locking it into position at the selected height. This permits a wide variety of exercises to be performed for exercising muscle groups of the arms and upper body. The amount of exercise resistance is adjusted by selecting more or fewer stacked weights. The range of available exercise resistance is thus determined by the quantity of available weights.
It would be desirable to have exercise resistance selectable over a greater range without requiring a correspondingly greater number of stacked weights.